stats: DogStatsd sink supports custom metric name prefix

api/envoy/config/metrics/v2/stats.proto

@@ -200,6 +200,10 @@ message DogStatsdSink {
   }
 
   reserved 2;
+
+  // Optional custom metric name prefix. See :ref:`StatsdSink's prefix field
+  // <envoy_api_field_config.metrics.v2.StatsdSink.prefix>` for more details.
+  string prefix = 3;
 }
 
 // Stats configuration proto schema for built-in *envoy.stat_sinks.hystrix* sink.

docs/root/intro/version_history.rst

@@ -84,6 +84,7 @@ Version history
 * rest-api: added ability to set the :ref:`request timeout <envoy_api_field_core.ApiConfigSource.request_timeout>` for REST API requests.
 * route checker: Added v2 config support and removed support for v1 configs.
 * router: added ability to set request/response headers at the :ref:`envoy_api_msg_route.Route` level.
+* stats: added :ref:`option to configure the DogStatsD metric name prefix<envoy_api_field_config.metrics.v2.DogStatsdSink.prefix>` to DogStatsdSink.
 * tcp_proxy: added support for :ref:`weighted clusters <envoy_api_field_config.filter.network.tcp_proxy.v2.TcpProxy.weighted_clusters>`.
 * thrift_proxy: introduced thrift routing, moved configuration to correct location
 * thrift_proxy: introduced thrift configurable decoder filters

source/extensions/stat_sinks/dog_statsd/config.cc

@@ -22,7 +22,7 @@ Stats::SinkPtr DogStatsdSinkFactory::createStatsSink(const Protobuf::Message& co
       Network::Address::resolveProtoAddress(sink_config.address());
   ENVOY_LOG(debug, "dog_statsd UDP ip address: {}", address->asString());
   return std::make_unique<Common::Statsd::UdpStatsdSink>(server.threadLocal(), std::move(address),
-                                                         true);
+                                                         true, sink_config.prefix());
 }
 
 ProtobufTypes::MessagePtr DogStatsdSinkFactory::createEmptyConfigProto() {

test/extensions/stats_sinks/common/statsd/statsd_test.cc

@@ -101,6 +101,22 @@ TEST_F(TcpStatsdSinkTest, BasicFlow) {
   tls_.shutdownThread();
 }
 
+TEST_F(TcpStatsdSinkTest, WithCustomPrefix) {
+  sink_.reset(new TcpStatsdSink(local_info_, "fake_cluster", tls_, cluster_manager_,
+                                cluster_manager_.thread_local_cluster_.cluster_.info_->stats_store_,
+                                "test_prefix"));
+
+  auto counter = std::make_shared<NiceMock<Stats::MockCounter>>();
+  counter->name_ = "test_counter";
+  counter->latch_ = 1;
+  counter->used_ = true;
+  source_.counters_.push_back(counter);
+
+  expectCreateConnection();
+  EXPECT_CALL(*connection_, write(BufferStringEqual("test_prefix.test_counter:1|c\n"), _));
+  sink_->flush(source_);
+}
+
 TEST_F(TcpStatsdSinkTest, BufferReallocate) {
   InSequence s;
 

test/extensions/stats_sinks/common/statsd/udp_statsd_test.cc

@@ -157,6 +157,26 @@ TEST(UdpStatsdSinkTest, CheckActualStats) {
   tls_.shutdownThread();
 }
 
+TEST(UdpStatsdSinkTest, CheckActualStatsWithCustomPrefix) {
+  NiceMock<Stats::MockSource> source;
+  auto writer_ptr = std::make_shared<NiceMock<MockWriter>>();
+  NiceMock<ThreadLocal::MockInstance> tls_;
+  UdpStatsdSink sink(tls_, writer_ptr, false, "test_prefix");
+
+  auto counter = std::make_shared<NiceMock<Stats::MockCounter>>();
+  counter->name_ = "test_counter";
+  counter->used_ = true;
+  counter->latch_ = 1;
+  source.counters_.push_back(counter);
+
+  EXPECT_CALL(*std::dynamic_pointer_cast<NiceMock<MockWriter>>(writer_ptr),
+              write("test_prefix.test_counter:1|c"));
+  sink.flush(source);
+  counter->used_ = false;
+
+  tls_.shutdownThread();
+}
+
 TEST(UdpStatsdSinkWithTagsTest, CheckActualStats) {
   NiceMock<Stats::MockSource> source;
   auto writer_ptr = std::make_shared<NiceMock<MockWriter>>();

test/extensions/stats_sinks/dog_statsd/config_test.cc

@@ -52,8 +52,10 @@ TEST_P(DogStatsdConfigLoopbackTest, ValidUdpIp) {
   NiceMock<Server::MockInstance> server;
   Stats::SinkPtr sink = factory->createStatsSink(*message, server);
   EXPECT_NE(sink, nullptr);
-  EXPECT_NE(dynamic_cast<Common::Statsd::UdpStatsdSink*>(sink.get()), nullptr);
-  EXPECT_EQ(dynamic_cast<Common::Statsd::UdpStatsdSink*>(sink.get())->getUseTagForTest(), true);
+  auto udp_sink = dynamic_cast<Common::Statsd::UdpStatsdSink*>(sink.get());
+  EXPECT_NE(udp_sink, nullptr);
+  EXPECT_EQ(udp_sink->getUseTagForTest(), true);
+  EXPECT_EQ(udp_sink->getPrefix(), Common::Statsd::getDefaultPrefix());
 }
 
 // Negative test for protoc-gen-validate constraints for dog_statsd.
@@ -64,6 +66,35 @@ TEST(DogStatsdConfigTest, ValidateFail) {
       ProtoValidationException);
 }
 
+TEST_P(DogStatsdConfigLoopbackTest, WithCustomPrefix) {
+  const std::string name = StatsSinkNames::get().DogStatsd;
+
+  envoy::config::metrics::v2::DogStatsdSink sink_config;
+  envoy::api::v2::core::Address& address = *sink_config.mutable_address();
+  envoy::api::v2::core::SocketAddress& socket_address = *address.mutable_socket_address();
+  socket_address.set_protocol(envoy::api::v2::core::SocketAddress::UDP);
+  auto loopback_flavor = Network::Test::getCanonicalLoopbackAddress(GetParam());
+  socket_address.set_address(loopback_flavor->ip()->addressAsString());
+  socket_address.set_port_value(8125);
+
+  const std::string customPrefix = "prefix.test";
+  sink_config.set_prefix(customPrefix);
+
+  Server::Configuration::StatsSinkFactory* factory =
+      Registry::FactoryRegistry<Server::Configuration::StatsSinkFactory>::getFactory(name);
+  ASSERT_NE(factory, nullptr);
+
+  ProtobufTypes::MessagePtr message = factory->createEmptyConfigProto();
+  MessageUtil::jsonConvert(sink_config, *message);
+
+  NiceMock<Server::MockInstance> server;
+  Stats::SinkPtr sink = factory->createStatsSink(*message, server);
+  ASSERT_NE(sink, nullptr);
+  auto udp_sink = dynamic_cast<Common::Statsd::UdpStatsdSink*>(sink.get());
+  ASSERT_NE(udp_sink, nullptr);
+  EXPECT_EQ(udp_sink->getPrefix(), customPrefix);
+}
+
 } // namespace DogStatsd
 } // namespace StatSinks
 } // namespace Extensions